A true three-dimensional volumetric display technology is a completely new three-dimensional image display technology, based on which a three-dimensional image having physical depth of field can be viewed directly. The true three-dimensional volumetric display technology will lead the scientific visualization into a new development area, and has broad application prospect. Briefly, a true three-dimensional display is a technology capable of reproducing image information in a true three-dimensional space which really has width, height, and depth. In the prior art, one feasible implementation is to form a voxel by exciting a material located within a transparent space in an appropriate manner, and by generation, absorption, or scattering of visible radiation.
The true three-dimensional volumetric display technology may be classified as a static imaging technology and a dynamic body scanning technology according to the way in which an imaging space is constituted. The imaging space of the static imaging technology is a stationary three-dimensional space, whereas the imaging space of the dynamic body scanning technology is a three-dimensional space formed by periodic motion of a display device.
The static imaging technology is as follows. In a three-dimensional space formed of a transparent material, two beams of laser are projected into an imaging space by an excitation source, the two beams of laser intersect at a point after subjecting to refraction, thereby forming a voxel which is the smallest unit constituting a volumetric image and having its own physical depth of field. Each voxel point corresponds to an actual point constituting a real object. Numerous intersection points are formed in the three-dimensional space when the two beams of laser move quickly, and thus a true three-dimensional volumetric image having true physical depth of field is constituted by numerous voxel points. The static imaging technology is limited in application because it can only generate a static image.
The dynamic body scanning technology is as follows. The imaging space thereof is formed by periodic motion of a display device, for example, a three-dimensional imaging space is formed by the rotary motion of a screen. In this technology, a volumetric image to be displayed is projected, in a manner of two-dimensional slice, onto a screen in a certain way, and the screen rotates at a high speed at the same time. What viewed by human eyes are not discrete two-dimensional pictures, but a three-dimensional volumetric image constituted by the two-dimensional pictures due to visual persistence of human eyes. However, since the structure of three-dimensional volumetric imaging in the dynamic body scanning technology is complicated, a mature and valid imaging structure for practical application does not exist at present. Further, the imaging manner thereof has a very complicated algorithm because it relates to intersection and disposition of a plurality of points, surfaces, and spaces.